Obesity-Induced Hepatic Steatosis Is Partly Mediated by Visceral Fat Accumulation in Subjects with Overweight/Obesity: A Cross-Sectional Study.

Introduction: We explored whether visceral fat accumulation mediates the development of hepatic steatosis in individuals living with overweight and obesity.

Methods: This cross-sectional study enrolled 769 outpatients with overweight and obesity aged 18-65 years. The controlled attenuation parameter (CAP) was used to quantify the degree of hepatic steatosis. Visceral fat accumulation, represented by the visceral fat area (VFA), was measured using magnetic resonance imaging. The associations of body mass index (BMI), VFA, and CAP with each other were assessed by univariate analysis, multivariate linear regression, and mediation analysis, respectively.

Results: Compared with women, male subjects had higher BMI, VFA, and CAP levels. In both sex, CAP was positively correlated with BMI and VFA by the univariate analysis. After adjusting for demographic and serum characteristics, the linear correlation coefficients between BMI and CAP were 1.738 (95% confidence interval (CI): 1.100, 2.377), 1.524 (95% CI: 0.798, 2.249), and 2.650 (95% CI: 1.292, 4.009) in all subjects, females, and males, respectively, while those between VFA and CAP were 0.190 (95% CI: 0.133, 0.247), 0.184 (95% CI: 0.117, 0.252), and 0.194 (95% CI: 0.086, 0.301). Mediation analysis showed that visceral fat accumulation contributed to 51.37%, 53.85%, and 26.51% of obesity-induced hepatic steatosis in the total, female, and male subjects, respectively.

Conclusion: Visceral fat accumulation partially mediates obesity-induced hepatic steatosis in individuals with overweight and obesity, especially in women. More focus on visceral fat reduction is needed in individuals with obesity.